The invention relates to a motion detection device, a system comprising such a motion detection device, a method for operating a motion detection device and a computer program to execute such a method.
Motion detectors are used to control peripheral devices, e.g., lighting in public spaces such as hallways or restrooms. When the lighting is off and a motion is detected, such as the movement of a person, the lighting will be switched on and remain on for a fixed period of time, measured by a timer. Whenever the motion detector triggers the timer again, the timer is reset to its initial value and the light will remain on for at least another such timer interval. When the timer expires, the light is switched off again.
An optimal timer period, for which the light shall be switched on, therefore should be long enough to not switch off the light as long as people are still in the area, but short enough to switch off the device shortly after all people have left the area. To ensure that the device does not switch off, while a person is still in the area but is out of reach of the motion detector or is not moving, the device is kept on for a specified time after the motion detector receives the last trigger.
The optimal timer period to keep the light switched on, however, will vary with time, such as the time of day or the weekday, in particular when considering the energy used by warming up a lamp. In order to accommodate the setting for all cases such that the light is never switched off while a person is present, the time interval has to be set conservatively. That way, the light often is switched on for too long and thus power is wasted.
U.S. Pat. No. 5,386,210 A describes a method and an apparatus for detecting motion for use in an illumination control monitoring of a particular area. Therein, three sensors are provided to enhance the ability to detect a presence in the area and to return to a pre-triggering configuration and a deactivation of the light within a predetermined duration of absence of motion or sound.
U.S. Pat. No. 6,933,685 B2 describes a lighting controller processing at least one of audio and video information in order to activate or adjust a lighting device based on a number of predefined behavioral rules.
Document US 2013/0069542 A1 and US 2012/0310376 A1 are directed to the detection of behavior patterns of occupants.
Document US 2013/0173064 A1 describes a heating, cooling and air conditioning unit (HVAC), which is programmable by a user and which is designed to learn behavioral patterns of its users in order to control the HVAC by analyzing the users' inputs.
WO 2013/058968 A1 describes a thermostat having an occupancy sensor to detect physical presence of users within a responsive area of the occupancy sensor. A processing system of the thermostat may therein be configured to determine, whether sufficient conditions are met regarding an occupancy condition to enable an away-state feature of the thermostat.
WO 2013/058969 A1 describes a thermostat including a plurality of sensors, with at least one sensor configured to detect the presence of a user within proximity of the thermostat, in order to activate the interface.
Document US 2013/0103622 A1 is directed to intelligent controllers that monitor, learn, and modify one or more control schedules that specify a desired operational behavior of a device, machine, system, or organization controlled by the intelligent controller.